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Emergency Contraception – Consumer Health Info

Publication Date: August 24, 2022

By: Joselyn Lantigua, Registered Nurse

What Is Emergency Contraception?

Emergency Contraception (EC) is a birth control method used after unprotected sex or when a primary form of contraception fails. It is generally used only in these specific situations and is not advised for use as regular contraception. It is also sometimes called “postcoital contraception.” EC is a contraceptive method that primarily works by either delaying ovulation or stopping the implantation of a fertilized egg. It does not protect against sexually transmitted infections (STIs) and does not induce an abortion.

How Effective Is Emergency Contraception?

The chart compares the four types of EC and illustrates how effective they are as well as other things to consider when making a choice.

Emergency Contraception Type Prescription required? How long after unprotected sex is it effective? Overall effectiveness Things to consider
Levonorgestrel Pills No Within 1-3 days (most effective) but can be used up to 5 days after 75-89% Most effective for people who weigh under 155 pounds. Effective for people between 155-195 pounds.
Ulipristal Pills Yes Within 5 days 85% Not the best option for people whose current hormonal methods of birth control (like the pill, patch, or ring) may have failed.
Oral Contraception Pills Yes Within 3 days ~75% Effectiveness varies based on the birth control that is going to be used as EC.
Copper IUD Yes; it needs to be inserted by a doctor or nurse practitioner Within 5 days 99.9% Once inserted, it can serve as the primary birth control method for 10-12 years (or until removed); effectiveness is not impacted by weight.

Additional Information on Emergency Contraception:

What Types of Emergency Contraception Are Available?

Emergency Contraception Pills

There are three types of EC pills available in the U.S. (they are also called “morning-after pills”). While each type of pill has its own pros and cons, it’s important to never use two different kinds (like Plan B and Ella) within five days of each other because the active ingredients may counteract one another and make the pills ineffective.

The first type is an EC pill that contains a hormone called levonorgestrel, which prevents an egg from being released from the ovary or being fertilized by sperm. This type of EC is sold under My Way, Plan B One-Step, Preventeza, and Take Action. This type of EC is most effective when taken up to 24 hours after unprotected sex, but it’s still effective up to 72 hours after unprotected sex. Most levonorgestrel ECs are accessible over the counter (OTC) and do not require a prescription.

The second type is an EC pill that contains ulipristal, which prevents the egg’s release, slows ovulation and also thickens vaginal fluids so it’s harder for sperm to reach the egg. This type of EC is sold under the brand names ella and ellaOne and requires a prescription. It is most effective when taken within 5 days of unprotected sex; unlike other EC pills, this type is just as effective for all five days (in other words, it doesn’t become less effective over time). A person’s weight has a big impact on this type of EC pill’s effectiveness, and it is more effective than other EC pills for people who weigh 155 to 195 pounds. This type of EC does not work as well for people who weigh more than 195 pounds. The third type of EC pill is regular oral contraceptive pills that are taken in a larger number than usual. Oral contraception already includes hormones like levonorgestrel, so taking more than one pill at a time works as EC. The number of oral contraception pills to take in order for them to work as EC depends on the brand used. This chart lists the number of pills needed for an EC dose for many different brands of oral contraception.

This type of EC is less effective than the others and is more likely to cause nausea. Women should consult with a doctor, nurse, or family planning clinic before using this type of EC; oral contraception requires a prescription.

Copper IUD


The copper IUD can also act as EC. It prevents pregnancy by interfering with the way that sperm moves, makes it hard for sperm to get to the egg, and also affects the uterus and Fallopian tubes. When used as EC, the copper IUD may act by preventing implantation, which is considered to be the beginning of a pregnancy. The copper IUD is sold under the brand name Paragard. To use a copper IUD as EC, a health care provider inserts it into a person’s uterus within five days of unprotected sex. If you can’t get an appointment to have the IUD inserted within five days after unprotected sex, use a different type of EC as soon as possible. This is the most effective type of EC and can then serve as your primary birth control for up to 12 years.

Which One is Right for You?
Planned Parenthood has an online quiz that can help you figure out which type of EC makes the most sense for you.

What Are the Side Effects?

Emergency Contraception pills have no long-term, serious side effects, and are safe for almost everyone to use. People who have a chronic medical condition should check with their health care provider before using any form of EC. The most common side effects from taking levonorgestrel and ulipristal pills are a difference in your period. It may come earlier or later, be heavier or lighter, or be spottier. After taking levonorgestrel pills, you may also experience lightheadedness or have tender breasts for a short while. There haven’t been any reports of serious complications from the use of ulipristal pills, but you may experience an upset stomach. Like EC pills, the copper IUD only rarely causes serious problems.

There are some harmless, but annoying, side effects from the copper IUD, including:

  • Mild to moderate pain when the IUD is inserted
  • Cramping or backaches for a few days after the IUD is inserted
  • Spotting between periods
  • Heavier periods and/or worse menstrual cramps

These side effects usually go away or happen less often within three to six months of insertion, after your body gets used to having the IUD in your uterus. You can read more about IUD safety and side effects on Planned Parenthood’s website.

Where Can I Get Emergency Contraception?

There are many ways that you can access emergency contraception! You do not need a prescription for levonorgestrel EC; it’s available over the counter (OTC) at local drugstores and pharmacies. It might be kept behind the counter or locked up to deter theft, but the pharmacist or store clerk can give it to you. According to Planned Parenthood, Plan B One-Step usually costs around $40-$50; Take Action and My Way cost about $15-$45. AfterPill (a generic brand of levonorgestrel EC) is available online for $20 plus $5 for shipping. (Note that AfterPill can’t get to you in time if you need EC right now, but you can buy it and have it on hand in case you need it in the future). Some health insurance plans cover EC pills although they may require a prescription to do so. You may also be able to get EC pills for free or at a reduced cost from Planned Parenthood or your local health department. You DO need a prescription for ulipristal EC. That’s because ulipristal is a different chemical than other types of EC. The Food and Drug Administration (FDA) requires specific approval before any prescription drug can be sold OTC, and never approves OTC sales until a drug has been available for a few years. (Ulipristal was approved in 2015, so the manufacturer is likely to request a shift to OTC status at some point). The easiest way to get the prescription is on-line. You may also be able to get a prescription for ulipristal EC from your health care provider, who may also send the prescription straight to your local pharmacy. Ulipristal EC usually costs at least $50 at the pharmacy or drugstore, but your health insurance may cover it. Getting a copper IUD requires an appointment with a health care provider like a gynecologist or family planning clinic. IUDs cost anywhere from nothing up to $1,000, depending on your health insurance. The good news is that IUDs are either free or low-cost under many health insurance plans, Medicaid, and other government programs.

What Else I Should Consider About Emergency Contraception?

  • Don’t take more than one kind of emergency contraception. As noted above, the active ingredients in different kinds of pills may counteract one another and make the EC ineffective.
  • Don’t take extra EC pills. Doing so won’t reduce your risk of pregnancy anymore, and you’re likely to feel sick or have other side effects.
  • Don’t panic if you feel sick to your stomach. You may experience mild nausea that goes away in a day or so. But, contact your health care provider if you feel really sick.
  • Call your provider if you throw up within an hour after taking EC pills. If you throw up, definitely call your health provider; you may need to repeat a dose and it might make sense to take anti-nausea medication.

Ask for an appointment right away if you have:

  • Severe pain in your calf or thigh
  • Several abdominal pain
  • Chest pain, cough, or shortness of breath
  • Severe headaches, dizziness, weakness, or numbness
  • Blurred or loss of vision
  • Trouble speaking
  • Jaundice (if you see a yellowish tint in the whites of your eyes, your skin, or your mucus membranes)

Remember that your next period may be a bit different. Your first period after taking EC might come a few days early or late. If you don’t get your period by the time you expect it, consider taking a pregnancy test. Start using birth control regularly. It’s not recommended to use EC as regular birth control, and EC doesn’t protect you against STIs (for that, you need a condom).



Other Resources:

  • The Mayo Clinic: a prestigious medical center with trustworthy medical information
  • Planned Parenthood: a non-profit organization that does research into and gives advice on contraception, family planning, and reproductive health
  • WebMD: a source of trustworthy medical news and information

Edited 11/8/2023 by Rachel Grimsley, RN, BSN, MSN, Nurse Writer

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